diff options
Diffstat (limited to 'math/w_scalb.c')
| -rw-r--r-- | math/w_scalb.c | 30 |
1 files changed, 27 insertions, 3 deletions
diff --git a/math/w_scalb.c b/math/w_scalb.c index dbfefaf9d5..0f1e2df8ef 100644 --- a/math/w_scalb.c +++ b/math/w_scalb.c @@ -45,9 +45,33 @@ sysv_scalb (double x, double fn) double __scalb (double x, double fn) { - return (__builtin_expect (_LIB_VERSION == _SVID_, 0) - ? sysv_scalb (x, fn) - : __ieee754_scalb (x, fn)); + if (__glibc_unlikely (_LIB_VERSION == _SVID_)) + return sysv_scalb (x, fn); + else + { + double z = __ieee754_scalb (x, fn); + + if (__glibc_unlikely (!__finite (z) || z == 0.0)) + { + if (__isnan (z)) + { + if (!__isnan (x) && !__isnan (fn)) + __set_errno (EDOM); + } + else if (__isinf_ns (z)) + { + if (!__isinf_ns (x) && !__isinf_ns (fn)) + __set_errno (ERANGE); + } + else + { + /* z == 0. */ + if (x != 0.0 && !__isinf_ns (fn)) + __set_errno (ERANGE); + } + } + return z; + } } weak_alias (__scalb, scalb) #ifdef NO_LONG_DOUBLE |